1. Field of the Invention
This invention relates to data communication system. The invention is more particularly directed to a method for reconverting digital data which is received through Time Division Duplex (TDD) process utilizing in a digital cellular communication system.
2. Background of the Invention
The TDD process is widely adopted for communication systems such as digital cellular communication systems. In the TDD process, frame by frame transmission and reception is alternatively performed by time division between a pair of movable subscribers, each using portable equipment such as telephones mounted in automobiles. In such communication, messages are relayed through a base station. The base station operates over a plurality of communication frequency channels. To communicate between a movable station and a base station, an unused channel is assigned. Then, frame by frame communication by time division is implemented over this assigned channel.
Both control signals and voice signals are transmitted in the digital cellular communication system. These signals are inserted into a frame and transmitted over the assigned channel. Depending upon the characteristics of these signals, they are encoded and inserted into the frame. By way of example the method of error correction encoding may depend upon bit length. However, the classification itself of these signals can not be specified or identified. Therefore, at the receiving side, a plurality of error correction decoding processes are implemented so that the properly decoded signals can be distinguished and determined to be corresponding transmitted signals before encoding. In case of the above example, two different decoding processes corresponding to two different error correction encoding techniques are used.
However, depending on the contents of the transmitted signals, it is possible for both of the two independent decoding processes to produce properly error corrected results. If this happens, the receiver is unable to judge which decoding result is proper. Though the above mentioned example was explained using two different signals (the voice signal and control signal of the digital cellular communication system) there is potential for the same problem to be encountered when more than two different signals are transmitted using TDD after implementing independent error correction encoding decoding to obtain the proper decoded signal.